First Interim Analysis of PROSPER Study Details Patient-Reported Symptom Burden of Mycosis Fungoides and Sézary Syndrome

Findings spotlighted in oral presentation at the 5th annual World Congress of Cutaneous Lymphomas meeting in Pasadena, CA Princeton, N.J., April 15, 2024 — On Friday, April 12, 2024, Professor Julia Scarisbrick of University of Birmingham presented interim findings from the Kyowa Kirin, Inc. (Kyowa Kirin, TSA: 4151)-sponsored study, “Real-World Observational Study of Mogamulizumab in Adult Patients with Mycosis Fungoides and Sézary Syndrome (PROSPER)”, a prospective observational study evaluating the real-world impact of mogamulizumab on disease symptoms and health-related quality of life (HRQoL) in patients with these subtypes of cutaneous T-cell lymphoma (CTCL). CTCL is a rare form of non-Hodgkin lymphoma that most prominently affects the skin, presenting as patches, plaques, tumors, or reddening of the entire skin, and may be associated with severe itching. In a proportion of cases, the disease may spread to the lymph nodes, blood, and/or other organs. In the current interim analysis, symptom scores (mean) were reported for 20 adult patients with relapsed or refractory disease (8 MF; 12 SS) over their first 16 weeks of mogamulizumab treatment. Prior to treatment initiation, patients reported their symptom burden using a 1 – 10 numeric scale. Skin itch (6.6), skin redness (6.2), flaking skin (5.9), and skin pain (4.0). Additionally, over half of patients reported having sleep problems either “frequently” or “every night” while 47% reported difficulties regulating body temperature “frequently” or “always”. Improvement in all symptoms was reported within 4 weeks of treatment initiation and by week 16, symptom severity had decreased considerably with the greatest improvement seen in skin redness (-2.9) closely followed by skin itch (-2.7), flaking skin (-2.5) and skin pain (-2.2). Of note, the proportion of patients reporting sleep problems or difficulties regulating body temperature either “frequently” or “always” decreased to less than 20%. “We know that CTCL patients not only suffer from the stress of a cancer diagnosis, but that these stresses are compounded by visual lesions and varying levels of discomfort,” says Scarisbrick, the study’s principal investigator. “The PROSPER study is helping us understand these burdens better and the impact mogamulizumab may have on patients’ symptoms and quality of life.” About PROSPER The objective of the PROSPER ( ID NCT05455931) study is to gain insight into the experiences of patients with MF/SS receiving mogamulizumab and of their caregivers in real-world clinical practice through the collection of patient-reported outcomes (PRO) data, enriched with qualitative data on disease and treatment experience and burden. The study was designed with input from patients and caregivers to ensure patient-relevant outcomes were selected. The study is being conducted in up to 6 countries across North America, Europe, and the Middle East, at 19 sites known to treat and follow-up patients with MF/SS. Patients are followed for up to 50 weeks from study enrollment. POTELIGEO® (mogamulizumab-kpkc) Indication POTELIGEO injection for intravenous infusion is indicated for the treatment of adult patients with relapsed or refractory mycosis fungoides (MF) or Sézary syndrome (SS) after at least one prior systemic therapy. Important Safety Information WARNINGS AND PRECAUTIONS Dermatologic toxicity: Monitor patients for rash throughout the course of treatment. For patients who experienced dermatologic toxicity in Trial 1, the median time to onset was 15 weeks, with 25% of cases occurring after 31 weeks. Interrupt POTELIGEO for moderate or severe rash (Grades 2 or 3). Permanently discontinue POTELIGEO for life-threatening (Grade 4) rash or for any Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Infusion reactions: Most infusion reactions occur during or shortly after the first infusion. Infusion reactions can also occur with subsequent infusions. Monitor patients closely for signs and symptoms of infusion reactions and interrupt the infusion for any grade reaction and treat promptly. Permanently discontinue POTELIGEO for any life-threatening (Grade 4) infusion reaction. Infections: Monitor patients for signs and symptoms of infection and treat promptly. Autoimmune complications: Interrupt or permanently discontinue POTELIGEO as appropriate for suspected immune-mediated adverse reactions. Consider the benefit/risk of POTELIGEO in patients with a history of autoimmune disease. Complications of allogeneic HSCT after POTELIGEO: Increased risks of transplant complications have been reported in patients who received allogeneic HSCT after POTELIGEO. Follow patients closely for early evidence of transplant-related complications. Adverse Reactions The most common adverse reactions (reported in ≥10% of patients) with POTELIGEO in the clinical trial were rash, including drug eruption (35%), infusion reaction (33%), fatigue (31%), diarrhea (28%), drug eruption (24%), upper respiratory tract infection (22%), musculoskeletal pain (22%), skin infection (19%), pyrexia (17%), edema (16%), nausea (16%), headache (14%), thrombocytopenia (14%), constipation (13%), anemia (12%), mucositis (12%), cough (11%), and hypertension (10%). You are encouraged to report suspected adverse reactions to Kyowa Kirin, Inc. at 1-844-768-3544 or FDA at 1-800-FDA-1088 or Please see full Prescribing Information as well as Patient Information. Disclosure Notice In line with Good Publication Practices (GPP) the study authors were not compensated for their participation. About Kyowa Kirin Kyowa Kirin aims to discover and deliver novel treatments with life-changing value. As a Japan-based Global Specialty Pharmaceutical Company, we have invested in drug discovery and biotechnology innovation for more than 70 years and are currently working to engineer the next generation of antibodies and cell and gene therapies with the potential to help patients with high unmet medical needs, focusing on bone/mineral, intractable hematological diseases/hemato oncology, and rare diseases. A shared commitment to our values, to sustainable growth, and to making people smile unites us across the globe. You can learn more about the business of Kyowa Kirin at: Contact: Susan Thiele Sr. Director, Product Communications & Advocacy Kyowa Kirin North America Phone: +1 (908) 736-4514
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